Use of second-generation antipsychotics like risperidone has been linked to hyperprolactinemia (HPRL), but most studies on antipsychotic-induced serum PRL level variations have been conducted in only adult populations and research findings on children and adolescents have yielded conflicting results.

New research in the journal International Clinical Psychopharmacology sought to investigate the relationship between risperidone therapy and serum PRL level in 34 drug-naïve children and adolescents. Patients began risperidone therapy at variable doses based on severity of symptoms (mean dosage 1.2mg/day) and mean baseline PRL was 17.98ng/mL. At follow-up (mean time of 5.5 months), serum PRL levels were on average 35.46ng/mL, a statistically significant difference compared to baseline measurements. In total, HPRL was detected in 20% of patients at baseline and 30% at follow-up. Differences in mean serum PRL values between baseline and follow-up were higher in female patients in the pubertal/postpubertal stage and for risperidone dose up to 1mg/day. Mean serum PRL increase was greater in early-onset schizophrenia spectrum psychosis patients vs. no-early-onset schizophrenia spectrum psychosis patients and in patients with a personal and family history of autoimmune diseases.

Even with a small sample size, the authors hypothesize that the increase in serum PRL levels could be related not just to the drug and its dosage, but also to sex, pubertal stage, psychiatric disease, and associated autoimmune disorders. Clinicians prescribing risperidone should assess all possible risk factors for HPRL in patients and monitor for clinical signs.